A digital beam forming method (DBF), a subspace method (SSM), a maximum likelihood method (ML), and the like are used to estimate a direction of arrival (DOA) of an arriving signal from a target (signal transmitting source or signal reflection object) with use of a plurality of sensors.
In order to perform a high-speed DOA estimation with high accuracy, International Patent Publication No. WO2006/067869 (Patent Document 1) discloses a technique of estimating a direction of arrival with use of a spatial average covariance matrix in which correlation vectors of baseband signals are combined.
The computation speed and robustness of the DOA estimation disclosed in Patent Document 1 can be improved in some aspects. It is, thus, an object of the present invention to provide a direction-of-arrival estimation apparatus, a direction-of-arrival estimation method, and a direction-of-arrival estimation program capable of high-speed estimation for a direction of arrival with high accuracy.